The VoicePark app could be the solution to San Francisco's parking problems. Photo: Jim Merithew/Cult of Mac

SAN FRANCISCO — A parking app that reliably helps find open spots in this congested city was coded on a turn-of-the-century tugboat in Sausalito.

The Terrapin served David LaBua as a coding den for VoicePark, a free app that uses sensors to monitor parking spots. It’s the only one we’ve tested to date that guided us to viable public spots on the busy streets of San Francisco.

“Parking is probably San Francisco’s biggest stressor, and writing about it has been very therapeutic for me,” says LaBua, who holds a master of science in psychology. “I had no intention of getting into the app game, but there was a real need for it.”

San Francisco is going after apps like MonkeyParking that let drivers cash in when they move their cars. Photo: Jim Merithew/Cult of Mac

SAN FRANCISCO — In a city obsessed with parking, app developers who came up with disruptive ideas to turn vacant spots into cash found their apps targeted by local officials. But the crackdown might be unnecessary: So far, the sharing economy seems to stall when it comes to auctioning off parking spots.

Cult of Mac offices are in the Mission District, epicenter of the parking crunch, so we took MonkeyParking and Sweetch — two of the “predatory” apps named in a cease-and-desist letter from San Francisco City Attorney Dennis Herrera — for a spin.